Telephone system



Feb. 14. 1933.

H. M. BASCOM SENDER /NVE/vro'f? H. M; BASC'OM By ATTORNEY Patented Feb.14, 1933 UNITED STATES PATENT OFFICE HENRY M. BASCOM, F BROOKLYN, NEWYORK, ASSIGNOR TO AMERICAN TELEPHONE ANI) TELEGRAPH COMPANY, ACORPORATION 0F NEVSVYORK TELEPHONE SYSTEM Application led January 18,1932. Serial No. 587,370.

This invention relates in general to dial telephone systems andparticularly to the illumination of the characters of the impulsesenders employed inv such systems.

In order to minimize the probability of telephone connections beinginaccurately established by a subscriber manipulating the impulse senderor calling dial in dimly lighted rooms, telephone booths and the like,it

has been suggested in the past that some means be provided for renderingthe dial characters more readily discernible. Treating the dialcharacters with phosphorescent paint, placing a lamp in proximity withthe dial, incorporating in the dial structure a translucent number platebeneath which a small lamp may be lighted constitute some of thesugU-estions proposed in the past. In cases where auxiliary lamps wereproposed,

means were provided for placing the lamps under the control of thetelephone receiver switchhook contacts to be lighted in a local circuitwhen the receiver was removed from its switchbook.

It is the object of this invention to improve the method of controllingthe illumination of telephone calling dials.

This object is attained in accordance-with a feature of the invention byemploying a glow discharge tube in the form of a neon lamp, suitablyassociated with the dial structure and operated by carrier frequencycurrent from the central office.

Another feature 'of the invention resides in the use of the neon lamp,not only as a means for illuminating the dial, but also as a dialingsignal to visually indicate to the calling subscriber when she mayactuate the dial in establishing a telephone connection.

These and other features of the invention will be readily understoodfrom the following detailed description made with reference to theaccompanying drawing in which Fig. 1 is a somewhat skeletonized circuitdiagram of an automatic telephone connection of the step-by-step typeembodying t-he features of the inventionand Fig. 2 is a schematicdiagram of an automatic telephone connection of the panel type embodyingthe features of the invention.

` to the bank of a line finder switch LF which is represented bythebrushes 6, 7 and 8. The line nder is connected by the tip and ringconductors 9 and 10 of th-e 'trunk T to an associated selector switch Swhich is represented by the brushes '11 and 12. The brushes 13 and 14represent a connector switch C which is connected by the trunk 15 to theterminals with which the brushes of the selectorS are in contact. The`line 16' connects the terminals vwith which the brushes 18 and 14 are incontact, to the called subscribers station B.` v

The line finder LF is similar to that disclosed in United States PatentNo. 1,711,682 issued to Hovland, May 7, 1929. The selector switch S andconnector switch C are of the Strowger type; for a detailed descriptionof their operation, reference may be had to pages 57 to 65 inclusive ofthe second edition of Automatic Telephony by Smith and Campbell. Onlythose portions of the various switches are shown as are required 75 inexplaining th-e operation of systems in which this invention isembodied.

When a call is originated by the removal of the receiver from thereceiver hook at the calling station A, the line relay 2O operates inthe well known manner, thereby causing a linender switch, such Aas LF,to hunt for the calling line 1. When the linefinder LFy has found thecalling line, the brushes 6, 7 and 8 will engage and remain inengagement with corresponding terminals of the calling line 1. 1

At this point in the connection, it is usua practice to cause a tonesignal to be transmitted over the line l to inform the callingsubscriber that the linefinder has found the calling line and that theconnection is ready for the reception of dial pulses. Upon hearing thistone signal, the calling subscriber proceeds to Yactuate the calling`dial 30 to 95 transmit pulses in accordance with the number of the linewith `which telephone connection is desired. It is common practice forthe calling subscriber to dial immediately after removing the receiverfrom the switch- 100 u p stepupY transformer in orde-r to: provide'suffihook without listening for the tone signal.

Suchagprocedure may result in the loss of pulses and the establishmentoa wrongconnection. n

' 5 `It will Vbe noted that a sourcel of'carrier current isnormallyassociatedwith the trunk T by wayv of. the-armatures and frontcontacts of .polarized relay 2l;` so that when the -trunk vTVisconnected tothe subscribers line 10 lg'carrier Vcurrent fromthe.source 3l Twill 4traverse a path includingthebaclrc'ontacts andarmatures of--relay 2l,t`runk conductors 9V and 10, brushes 6 and 7 `oflinenderLF -snbscribers substation yeou'lipmentfat station A. A neonlamp'23 isbridged across the secondarywinding ofthe transformerV 22, andV is,energizedfaccordingly, by currentfrom thej source 3 1, VTheillumination of lamp 23 there- Vu .ponindicates to the callingsubscriber thatv Shelmay proceed to dial.V Y

diait vcharacters.

and! the mechanismV of the, dial;y The char- `v actors: may-be stampedon ja'translucent ma- -teriall supported by a metal platewith per!Vforations, in it corresponding tothe location 3? ot the. characterstoqperrnit thernjto be illnm'inatedrom the rear. `j v l V Theqlamp 23is'showniconnected:witha.

cientyvoltage for propieroperation.` i, 4Q From the foregoingdescriptiomit isfevi-y d entthat this invention provides not' only a"satisfactory *.metliodf: of illuminatingi agiteljefV phone callingdialbut alsolftirnishes a visual nali..

scriberi proceeds to Vdial thev desirednumber and the selector 'switchVSV andV cmancctorv c switch@ function in the Welt knownmanne-rrespOIlSc to the transmitted HPUJSQSim"` complete; the connectionto" the! called `sta'- thepolarized relay-21 remains unoperated as itispoled in'such a-rnannerthat current from;V Y i the-batteryconnectedtothe connector circuit by wayofthe windings of relay 24;- zmdnor- @itmalcontactsfoai :relay 25` does notcause it `to opera-te;v

` AThe called' subscriber ing' responding to` the 1 incomingsignalremovejs the receiver at sta- Vtion B whereupon relayoperates overan Q65. obtiens circuitfand establishesfan obvious Up vnfreceiptvisualeffected f by thefilltnfnination of neon lampi 23, thesubs'- noted thatup until;thistime,x

circuit for reversing relay 25 which operates.

In operating, relay 25 reverses the leads from battery and groundassociated with relay 24 to the tip and ringk conductors of theestablished connection. This elects a reversal of current throughpolarized, Vrela-y 2].. which operateszand removes-the source 31 ofcaris thereupon extinguished.

rier current from theV trunk T. The lamp 23 ft'Y thej termination ofconversation be! tween "thef subscribers at stations A and B, theconnection is released inthe well known lmanner. "l and thelr associatedVline terminals, p.r1mary n 15. winding of transforme'rQQl landthroughthe In Fig;,2there isdisclosed diagrammatif cally,` one methodofapplying the present in-` vention toal panelty'pe syste-m. jIn thisiigure, LF representsla, lineiinderT SS a sender "selector,y DS adistrict. selector', IStan income? ing selectorandFS atina-,lselector-VThese.

switches; function. in a] wellknown vI nanner fandit:isbelievcdnnnecessary tof enter-finto. n

any detailed-descriptionof their operation inthisapplicationHowevensuchj a systemV is Ldisclosedand described S. latent`'1,567,07252issued to W1 Matthiesgl-Decemb er 29,1- 9'25l`f 1 1 .n Itiswell wn that infsuch panel,type systems-7 theA remoyaLf-otthe -receiverat a; calling; ',station such as station A causes a sender-selectorswitch to functiontoY select ani lle"^-seriderl such asis`diagranimatically gli shown atSrandrconnect itwith a lineiimder isnfch"as- LFy which is Vlinnting for the calling line-n ln 'ith-1sycase,:the source' 3l of v carrier frequencyicur-rent 1s bridged acrossthe sender conductorsV so? thatwhen the VseI-idergSisconncctedtoj-thecalling linel by way otlinefinder LEand senderselcctor SS,.Car-rier cur-- .7 rent from the Vsource 31 will-traverse.thepri# mary 'winding oi transformer' 22 over-'an ohnio'ns circuiti andthe lamp, 23- w'illgbe energized to serve both, fas alk dialing,signaland aszafmean'sfor illuminatingthc gd-ial chari When-:theconnection has beenk tothe ycalled sta-tion bytway of the'districtf`selector DS, 'incoming-'selectorgIS and sel'ector FS i and thevdistrict selector vhas causcd'thetalkingI connection to be established'the sender Sj'is dismissed in a manner well knowntof those skilled inthe art', The' disconnection vof the sender alsodisconnccts Y thecfurrentsource- Sl-k, from` the corinectionso that the lamp 23 isextinguished.V Y In' both stepfbyfstep andv panel type: systems,A thisinvention pro-vides Vforythe transl mission ot.. a visual,L signal; toindica? e toi the f cal-ling subscriber that vthe telephone; equipment,is prepa-red iorzdialing and also. tol `ilhiminate' tl1e-dial'charactersV v r v Wha-tis claimed; is:

1 ll., telephone system,l callingstation;- i

a- VdialV calling station, an aut@maticV switch controlled by thevoperation etY dial, switching means responsive to the removal of thereceiver at said calling station for connecting said station with saidautomatic switch, a visual signal at said calling station and meanseffective upon the connection of said automatic switch with said callingstation for energizing said visualsignal.

2. In a telephone system, a calling station, dial at said callingstation, an automatic switch controlled by the operation of said dial,switching means responsive to the removal of the receiver at saidcalling station for connecting said station with said automat-ic switch,a lamp at said calling station and means effective upon the connectionof said automatic switch with said calling sta tion for causing saidlamp to illuminate said dial and give a visual dialing signal.

3. In a telephone system, a calling station, a dial at said callingstation, an automat-ic switch controlled by the operation of said dial,switching means 1responsive to the removal of the receiver at saidcalling station for connecting said staion with said automatic switch, avisual signal at said calling station and a source of carrier currenteffective upon the connection of said automatic switch with said callingstation for energizing said visual signal.

4. In a telephone system, a calling station, a called station, a dialatsaid calling station, a plurality of automatic switches cont-rolled bysaid dial, switching means responsive to the removal of the receiver atsaid calling station for connecting said dial with the first of saidautomatic switches, a lamp located at said calling station, meanseffective upon the operation of said switching means for energizing saidlamp and means effective upon the response of the subscriber at saidcalled station when said automatic switch-es have completed theconnection betweensaid called and calling stations under control of saiddial, for extinguishing said lamp.

5. In a. telephone system, a calling station, a lamp signal thereat,alink circuit, switching means responsive to the removal of the receiverat said calling station f'or connecting said station to said linkcircuit, and means effective upon the connection of said station withsaid link circuit for energizing said lamp signal.

6. In a telephone system, a calling station, a neon lamp signal thereat,a link circuit, a source of alternating current normally connected tosaid link circuit and switching means respon sive to the removal of thereceiver at said station for connecting said link circuit to saidcalling station to cause said neon lamp signal to he energized bycurrent from said alternating current` source.

7. In a telephone system, a` calling station, a dial thereat, means forilluminating the characters of said dial, a link circuit, meansresponsive to the removal of the receiver at said calling station forconnecting said calling station to said link circuit and means effectiveupon the connection of said calling station to said link circuit forenergizing said illuminating means.

8. In a telephone system, a calling station, a dial thereat, a neon lampassociated with said dial for illuminating the characters of said dial,a link circuit, a source of alternating current associated with saidlink circuit, switching means responsive to the removal ofthe receiverat said calling station for connecting said calling station to said linkcircuit whereupon current from said source energizes said neon lamp.

9. In a telephone system, a calling station, a dial thereat, means forilluminating the characters of said dial, a link circuit, meansresponsive to the removal of the receiver at said calling station forconnecting said station with said link circuit, means responsive to theconnection of said station with said link circuit for energizing saidilluminating means, a plurality of automatic switches, a called station,said automatic switches being edective upon the actuation of said dialfor extending a connection from said link circuit to said called stationand means responsive to the removal of the receiver at said` calledstation for causing the deenergization of said illuminating means.

10. In a telephone system, a calling line, a dial thereat, means forilluminating the characters of said dial, a link circuit, meansresponsive to the removal of the receiver on said calling line forconnecting said line with said link circuit, a relay` in said linkcircuit, a source of current connected to said link circuit by way ofthe contacts of said relay from which said illuminating means isenergized when said calling line is connected to said link circuit, acalled line, switching means responsive to the actuation of said dialfor extending av connection from said link circuit to said calledstation and means at said called station for causing said relay tooperate and disconnect said current source from said link circuit.

1l. In a telephone system, a calling line, a dia-l associated therewith,a lamp for said dial, an automatic switch, means associated with saidcalling line for causing said automatic switch to hunt for and seizesaid calling line and means responsive to the seizure of said line bysaid switch for energizing said lamp to illuminate said dial.

In testimony whereof, I have signed my name to this specification this15 day of January 1932.

HENRY M. BASCOM.

